According to the prior art, so-called suction walls consist of a wall-type structure, a large surface of which is equipped with suction power, to suck in and filter the aeriform pollutants that develop through the effect of a certain processing carried out near to the wall itself. Compared to more complex structures such as actual rigid cabins, suctions walls offer more flexibility of use, in particular thanks to particularly advantageous embodiments that make transportability possible by fork lift trucks, and that may be equipped with extensible tunnels that, projecting from the wall, circumscribe and physically isolate the area of processing on the sides and on top, decreasing dispersions of pollutant and increasing the efficiency of the suction. Suction walls moreover ensure substantially better results than simple suction tubes or arms.